Tuberculosis (TB).
Caused 1/3 of deaths among healthy adults in the 19th century
Today >1 billion infected (20% of world population)
In U.S. common among homeless, malnourished, elderly or alcoholic poor

Mycobacterium tuberculosis

Meningitis. Meningococcemia. inflammation of the meninges (membranes lining the central nervous system)
can be caused by viral or bacterial infections, or can be aseptic